A casual reunion of three longtime buddies slouching unprofitably through their 30s ultimately betrays a darker purpose in “Small Engine Repair,” a raw, funny and well-tooled new play written by and featuring John Pollono, who is making an impressive, double-barreled Off Broadway debut.

Mr. Pollono was born in New England but currently works as an actor and writer in Los Angeles. He’s returned to his roots, after a fashion, in “Small Engine Repair,” which is set in a greasy garage in Manchester, N.H., and opened on Wednesday night at the Lucille Lortel Theater, in an MCC Theater production. (Given the play’s successful earlier run in Los Angeles at Rogue Machine Theater, I’m surprised Mr. Pollono hasn’t already been snapped up by the hungry maw of television.)

Mr. Pollono’s Frank Romanowski plies the trade of the title. He had bigger plans for his life, but his girlfriend got pregnant when he was a high school junior. Frank became a young father and had to make a living, and he essentially raised his daughter, Crystal, himself. She’s now 17: roughly the age at which her father’s and mother’s lives were so irrevocably altered, a fact that will come to have haunting significance as the screw turns of Mr. Pollono’s nifty, suspenseful plot are set in motion.

Although he is not making a killing fixing snowblowers and lawn mowers, Frank is actually doing better than either of the guys he’s invited over to party as the workday winds down. Packie (James Ransone) mostly drinks away his days, and is still living in his grandmother’s basement. Swaino (James Badge Dale) looks slicker, boasts endlessly about his conquests (“My secret to youth? Don’t date ’em over 26”) and holds a warehouse job — but he still owes Frank some money.

Since Packie and Swaino had a falling-out — something involving cough drops, an ethnic slur and lots of booze — Frank’s convening of this once tight threesome takes them both by surprise. (He gave each a different reason for wanting to see him: Packie got a hazy story about a possible cancer diagnosis; the sex-obsessed Swaino was lured with the promise of strippers.) As these two tensely square off to renew old grievances, Frank calms the waters with generous lashings of beer and whiskey (both Jameson and Johnnie Walker Blue).

High-end liquor for these low-living types? It’s a signal that Frank has something serious up his oil-stained sleeve. As “Small Engine Repair” zips along (the play runs just 70 minutes), with crackling comic dialogue steeped in the tang of male aggression and rivalry, it’s easy enough to spot Mr. Pollono’s stylistic influences.

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From left, James Ransone, John Pollono and James Badge Dale as three longtime friends who share both affection and tensions in shifting degrees.CreditSara Krulwich/The New York Times

At the top of the list would be David Mamet, that supreme specialist in dramatizing the sexual and psychological pathologies of the American man in crisis. Mr. Pollono’s dialogue has some of the same brazen vulgarity and acrid humor of Mr. Mamet at his best. And when “Small Engine Repair” takes a sudden turn for the violent, the play gives off a whiff or two of Irish peat, courtesy of Martin McDonagh. (Swaino’s mockery of Packie’s Irish heritage suggests a sly tip of the hat.)

But while Mr. Pollono has clearly absorbed influences from his peers and forebears, he folds them into a clever plot that could have been cooked up only in the social networking era, putting a new engine in a classic dramatic plot: a man’s hunger for retribution. It would spoil the creepy fun to reveal more, other than to say the match that sets things ablaze is the arrival of a most unlikely visitor, the college kid Chad (Keegan Allen), whose clean-as-a-whistle Top-Siders and pastel polo shirt blazon forth his membership in a rather higher social class than Frank and his buddies.

Frank has connected with Chad to buy some ecstasy to put a capper on the festivities, but once the deal has gone down, Chad settles in to share a little booze and pot with the guys. This proves to be a spectacularly unwise decision.

Mr. Pollono is not yet a fully mature playwright. Some of the script’s developments can be seen peering around the corner, and characters come and go a little awkwardly. While they are written in bold colors and crisply individualized, these people lack the emotional depth that would make “Small Engine Repair” more than a shivery, funny revenge comedy.

But there is more substance here than might first appear. The play puts a subtle focus on the divide between the generations caused by the sudden boom in social media. (Foursquare, the check-in app, plays a major supporting role.) New technologies have altered the social and sexual culture of young men and women today, opening up potentially dangerous new fault lines. A young life can come undone before a kid has reached drinking age through a thoughtless tweet or a photo unwisely texted. (The play obliquely brings to mind the tragic case of Tyler Clementi, and the grim stories of teenage girls hounded by cyberbullying.)

The excellent cast, under the taut direction of Jo Bonney, keeps you from dwelling too long on any flaws in the writing. The testy comic banter between Mr. Dale’s cocky Swaino and Mr. Ransone’s insecure, jittery Packie is scorchingly funny (if almost impossible to quote from, laced as it is with crudities). Mr. Keegan’s smoothly arrogant Chad is a precise portrait of 21st-century entitlement, junior class.

Although Mr. Pollono’s role is not the flashiest, he is also terrific as Frank. Because he exudes a tight-lipped sense of wanting to keep the peace, we never sense how much is at stake for him on this seemingly breezy evening. It then becomes clear in a terrible flash that Frank’s surface good nature has been a carefully planned decoy. Underneath, boil emotions of a very different kind.

Correction:

A theater review on Tuesday about “Small Engine Repair,” at the Lucille Lortel Theater in Manhattan, misstated the date the play opened. It was Wednesday night, not Monday night. (It had been in previews and was originally scheduled to open Monday.)